The guy that set up this site evidently bought a part of Bill Graham's archived recordings and they are available to stream free for the lisening. King Buscuit Flour hour stuff is here also:

http://concerts.wolfgangsvault.com/

Eventually, the music may be available to download for a fee.
_________________________
"I didn't care what she didn't 'low--I would boogie-woogie anyhow" John Lee Hooker